1. Field of the Invention
This invention is related to electrical connectors and especially to electrical connectors that have molded latches forming a part of a molded connector housing. These molded latches serve as primary retention members to secure electrical terminals or contacts in the housing. This invention is also related to electrical connector assemblies that uses a mechanical assist, such as a lever, to overcome large mating forces between connectors having a large number of mating terminals or contracts mounted in two mating connectors.
2. Description of the Prior Art
Crimp snap terminals are commonly used in mating electrical connectors that employ a large number of mating terminals. These terminals are first crimped to wires that may be part of an electrical harness, and the terminals are then inserted into cavities in a molded connector housing. Many of these conventional crimp snap terminals have metal tangs or lances protruding from the terminal. These tangs or lances are deflected as the terminals are inserted into the housing cavities, and the lances then snap back to their normal position engaging a surface on the connector to secure the terminals in the housing cavities after they have been completely inserted. In many applications, such as automotive and motor vehicle assemblies, these protruding metal lances pose problems. The protruding lances can become snagged on the wires causing difficulties during assembly, or the lances can be damaged so that they do not adequately retain the terminal in the housing. When two connectors are mated, and mating force between terminals can then dislodge improperly seated terminals.
An alternative to the use of metal lances is to mold resilient plastic latches as part of the molded electrical connector housing. These molded latches are typically located on one side of the housing cavities in which the terminals are positioned. When the terminals or contacts are inserted, each plastic latch is separately deflected outwardly to permit the terminal to move to its fully seated position. When the terminal is fully seated, the plastic latch can return to its neutral position where it will engage a shoulder or and edge of the terminal to retain the terminal during mating. In many of the connectors of this type, a gap is formed between the plastic latches and an adjacent housing wall, typically an outer housing wall. The adjacent wall then serves as a back-up preventing excessive deflection of the molded latch, either during terminal insertion or removal. Often a separate terminal position assurance member is then inserted into the gap between the wall and the molded latch. This terminal position assurance member can only be inserted into this gap if the terminal has been fully inserted allowing the molded latch to return to its normal position. However, the need to provide a back-up wall and a gap to provide space both for latch deflection and for insertion of a terminal position assurance member results is a larger connector by increasing the height of the housing.
Some prior art electrical connectors have eliminated the outer back up wall from the housing and have placed the molded latches on an external surface of the connector housing. Representative examples of this approach are shown in U.S. Pat. No. 4,891,021 and in U.S. Pat. No. 4,984,998. However, to prevent excessive deflection of the molded latches and overstressing of the plastic, these prior art connectors have still employed overstress projections which limit outward deflection of the molded latches. These overstress projections can also add height to the connector housing unless they do not extend beyond connector latches or other structures located on the exterior of the housing. However, when the sides of the connector are otherwise free of projecting structures, these overstress projections increase the size and height of the connector. The size of the opening or pocket in which the connector is to be located is thereby affected, or the spacing on which the connectors are to be mounted is adversely affected.
Another prior art approach that has been employed to back-up molded latches located on the exterior of the housing is to use an outer shell that fits over the external latches and is usually inserted over the mating end of the housing or from the side. This shell can protect the molded latches when the connector is in use, but they can only be assembled after the terminals have been fully inserted. The shells therefore serve as a terminal position assurance member, but they do not function as a back-up or anti-overstress member to protect the molded latches during terminal insertion or removal. These outer shells also add another layer with a resultant increase in the height and size of the electrical connector assembly.
One application in which the height or lateral dimension of an electrical connector is important is when the connector must be mated in a shroud or shield, especially one having a standard or predetermined size. For example, U.S. Pat. No. 5,322,448 discloses am electrical connector having a lever actuated mechanism for mating a connector containing receptacle contacts to a pin header. That connector includes an outer shroud or shield to which a lever mechanism is attached. An electrical connector is fitted into a pocket in the shroud and the lever engages a rack on a mating pin header to simplify mating two multi-position electrical connectors. Although not included in that disclosure, the electrical connector, with which that assembly is used, employs contacts having metal lances to secure the contact in the connector housing cavities. However. as previously discussed that configuration requires less space than a conventional connector employing molded plastic contact retention latches.